Polio case reported in New York, the first US case since 2013. Investigators are looking into where the case came from.

A case of polio has been reported in New York, Rockland County officials said Thursday. The viral disease, which can cause neurological symptoms, paralysis or death, was declared eliminated in the U.S. in 1979.

Although routine spread has been halted for decades, occasionally travelers with polio have brought infections into the U.S. In 2013, a case occurred in a 7-month-old who had recently moved to the U.S. from India.

The patient in the new case, a young adult who did not recently travel outside the country, was hospitalized but is no longer, officials confirmed. Officials said the person had presented with paralysis but wouldn’t say if the patient was still dealing with that side effect.

The person had not been vaccinated against polio, health officials said.

The person is no longer able to transmit the virus, officials said. But investigators are looking into how the infection occurred and whether other people may have been exposed to the virus.

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According to the state Department of Health, sequencing on this case showed it was revertant polio Sabin type 2 virus. This points to a transmission chain from an individual who received an older form of oral polio vaccine that hasn't been used in the U.S. in over two decades.

The new case may stem from someone who got such a vaccine outside the U.S. and spread the vaccine-derived strain of the virus, officials said. State Sen. Elijah Reichlin-Melnick said the case appeared to have come from outside the U.S.

In the 2013 case, the child also had the type of polio found in the live form of vaccine used in other countries.

There are two types of polio vaccines. Since 2000, only inactivated vaccines are given in the U.S., health officials said, so there is no risk of getting polio from the shot.

But some countries where polio has been more of a recent threat use a weakened live virus that is given to children as drops in the mouth. In rare instances, the weakened virus can mutate into a form capable of sparking new outbreaks.

Rockland County Executive Ed Day and County Health Commissioner Dr. Patricia Schnabel Ruppert encouraged residents who are unvaccinated or have not completed the polio vaccination series to get vaccinated as soon as possible.

"Many of you may be too young to remember polio, but when I was growing up this disease struck fear in families, including my own. The fact that it is still around decades after the vaccine was created shows you just how relentless it is," Day said. "Do the right thing for your child and the greater good of your community and have your child vaccinated now."

The county has scheduled a polio vaccination clinic for July 22.

Polio usually is transmitted by mouth, usually from hands contaminated with the fecal matter of an infected person. It can also be transmitted through saliva by oral-to-oral or respiratory contact.

Up to 95% of people infected with polio have no symptoms, yet they can still spread the virus. Most who do have symptoms get a fever, muscle weakness, headache, nausea and vomiting. Up to 2% of infected people develop severe muscle pain and stiffness in the neck and back; less than 1% of cases result in paralysis.

Polio is endemic in Afghanistan and Pakistan, although numerous countries in Africa, the Middle East and Asia have also reported cases in recent years.

In June, health officials in Britain warned parents to make sure children have been vaccinated because the poliovirus had been found in London sewage samples. No cases of paralysis were reported.

Polio vaccines were first introduced in 1955, with improvements later made through research done at the former Lederle Labs, located in Rockland County. The vaccine has long been a standard childhood immunization.

U.S. children are still routinely vaccinated against polio. Federal officials recommend four doses: to be given at 2 months of age; 4 months; at 6 to 18 months; and at age 4 through 6 years. Some states require only three doses.

According to the CDC's most recent childhood vaccination data, about 93% of 2-year-olds had received at least three doses of polio vaccine.

For more information on polio, its symptoms, and how it spreads, visit NYSDOH's page here. New Yorkers can learn more about the polio vaccine available in the U.S. at the CDC's page here.

Contributing: The Associated Press

This article originally appeared on Rockland/Westchester Journal News: New York polio case first in US since 2013. Where is 2022 case from?